Islamabad , Pakistan -LRB- CNN -RRB- -- Bomb blasts in Pakistan rocked three police buildings near Lahore , police told CNN on Wednesday .

Police chief Ghulam Mehmood Dogar said the three bombs were planted on Tuesday night at a police station , an office of a senior police official and a police barracks .

They were detonated by remote control this morning in the city of Gujranwala , 70 kilometers northwest of Lahore , Dogar said .

Three police officers were injured and parts of the buildings were damaged .

The first two explosions happened within 30 minutes of one another , and the third bomb was detonated about three hours later .

Gujranwala has been largely free of the militant violence plaguing parts of Pakistan .

Police said there was no immediate claim of responsibility for the attacks .

On Monday , two people were injured when in back to back explosions at police stations in the southern port city of Karachi .

Journalist Nasir Habib contributed to this report

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Gujranwala has been largely free of the militant violence

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Three police officers were injured

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The explosives were detonated by remote control